Yes, this is the first time with utility light sussex.
I purchased a breeding trio of utility birds (Hams bred cockerel onto Smith bred pullets) and have, 3 weeks ago, hatched 13 live chicks from 14 fertile eggs. I have also been in contact with Graham Bellingham with regards to purchasing hatching eggs from his Fred Hams line early in 2017.
I'm told that Nick Smith (
http://www.practicalpoultry.com/news/303-sussex-supremo-retires) and Fred Hams are/have been the leading light in utility light sussex breeding for many years.
The reason I asked the initial question about separating the growers by breed or by sex, was that 2 of the chicks in your 2nd photo this morning seem to have pea combs and blotchier feather markings, which could suggest they are IGxLS males.
My intention was to use a jubilee indian game cockerel over light sussex pullets to produce a white feathered bird which looks cleaner when dressed, but of my indian game chicks which hatched from 2 different sources, the 2 dark indian game growers were over 200g heavier each than the jubilee and blue chicks at 9 weeks. Is there a growth pattern amongst the 3 colours, or just the way it's happened with these few?
Keep up the good work, as I'm sure there are quite a few of us watching from the wings.